Suggestion for Red Hat IDM

Hello
I am setting up Red hat IDM solution for my organization. The implementation is based on One-way cross domain trust with Active directory. I am not using IDM DNS service as my organization already has AD DNS which is well established globally. Planning to create sub-domain in AD and add only the IDM server to the sub-domain and to keep the clients in AD domain itself. So that A record for clients will be managed in AD DNS and polices in IDM server.

Any pros and cons with this approach ?

Thank you